Which of the following has the highest glycemic index?

HP CHO -9 October 2022

Biochemistry & Nutrition

Easy

Appeared in: HP CHO -9 October 2022

Explanation

Dextrose is chemically identical to glucose, which serves as the reference standard for the Glycemic Index (GI) scale and is assigned a value of 100.
By definition, it causes the fastest and most significant rise in blood glucose levels compared to other carbohydrates.
Foods are ranked on the GI scale based on how their effect on blood sugar compares to that of pure glucose (dextrose).

Option A: Ice cream has a low to medium GI (around 35-60). The presence of fat and protein slows down the digestion and absorption of its sugar content, resulting in a more gradual rise in blood sugar compared to dextrose.
Option B: Cucumber is a non-starchy vegetable with very few carbohydrates. Consequently, it has a very low GI (less than 15) and has a minimal impact on blood sugar levels.
Option C: While white bread has a high GI (around 70-79) due to its refined carbohydrates, it is still lower than that of pure dextrose, which is the benchmark at 100.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Glycemic Index of Common Foods as background academic context rather than a clinical decision trigger.
Nurses use the concepts of Glycemic Index (GI) and Glycemic Load (GL) for patient education, particularly for individuals with diabetes mellitus, to help them manage blood sugar through dietary choices.
Understanding GI helps in recommending appropriate carbohydrate sources to prevent rapid spikes (hyperglycemia) or drops (hypoglycemia) in blood glucose.
What if? If a patient with diabetes experiences a hypoglycemic episode (low blood sugar), a nurse would recommend a high-GI source like dextrose tablets, fruit juice, or honey for a rapid increase in blood glucose, rather than a low-GI food like an apple or whole-grain crackers.

How to Approach the Question

First, identify that the question asks to find the food with the 'highest glycemic index'.
Recall the definition of the Glycemic Index (GI): a scale from 0 to 100 that measures how quickly a carbohydrate-containing food raises blood sugar levels.
Remember the reference standard for the GI scale. Pure glucose is assigned the value of 100.
Analyze the options. Recognize that 'dextrose' is another name for glucose.
Based on the definition, dextrose must have a GI of 100, which is the highest point on the standard scale.
Compare the other options: Bread (high GI, but less than 100), Ice-cream (medium GI due to fat), and Cucumber (very low GI). This confirms that dextrose is the highest.

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